The present invention relates to an isothermal terminator and to a method of determining a shape of an isothermal terminator.
In typical radio frequency (RF) terminator assemblies, a cone shaped terminator is disposed within a waveguide through which RF radiation propagates toward an absorptive exterior surface of the cone shaped terminator. An interior surface of the terminator is on an opposite side from the exterior surface and, with the RF radiation incident on the exterior surface such that the RF radiation is absorbed by the cone shaped terminator, infrared (IR) radiation is emitted from the interior surface. The IR radiation emitted from the interior surface is detectable as an IR scene by an IR scanner positioned downstream from the terminator.
The cone shaped terminator has its conical shape because the conical shape promotes RF absorption and minimizes reflections. However, the conical shape also leads to thermal gradients being generated within the material of the cone shaped terminators. This thermal gradient leads to problems with the RF terminator assemblies being used in certain applications.